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History and some Cognitive
Neuroscience (Chapters 1 & 2)
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History
Timeline showing early experiments studying the mind in the 1800s
and events associated with the rise of behaviorism in the 1900s
Gustav Fechner!
1801-1887
Psychophysics!Fechner color effect:!http://www.itp.uni-hannover.de/~zawischa/ITP/benhamtop.html!
Fechner"s Law – a subjective sensation is proportional to the logarithm of the stimulus intensity!
S = K Log I!S = Psychological sensation!I = Physical intensity of the stimulus!
I * 3 = S + S!I * 3 * 3 = S + S + S!
Geometric increase in stimulus intensity leads to an additive increase in sensation.!
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Unconscious inference
•# Some of our perceptions are the
result of unconscious assumptions
we make about the environment
•# We infer much of what we know
about the world
Hermann Von Helmholtz!
1821-1894
Influenced Ebbinghaus, Wundt, Helmholtz!
Math Modeling!The mind and body are different sides of one reality.!
"Every sensation, presents itself as an indivisible unit; and it is quite impossible to read any clear meaning into the notion that they are masses of units combined."!
William James!
1842-1910
Gustav Fechner!
1801-1887
Timeline showing early experiments studying the mind in the 1800s
and events associated with the rise of behaviorism in the 1900s
Pavlov (1849-1936) Thorndike (1874-1959)
History
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Pavlov (1849-1936)
Thorndike (1874-1959)
Classical (Pavlovian) Conditioning!(Dogs)!CS – !UCS –!UCR – !CR –!
Law of Effect!(Cats)!Puzzle Box!Precursor of $Operant" or $Instrumental" Conditioning!
Alpha, Beta Tests (ASVAB)!$Active Learning"!
Pavlov’s Discovery:
Classical
Conditioning
Timeline showing early experiments studying the mind in the 1800s
and events associated with the rise of behaviorism in the 1900s
Pavlov (1849-1936) Thorndike (1874-1959)
History
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Timeline showing early experiments studying the mind in the 1800s
and events associated with the rise of behaviorism in the 1900s
Pavlov (1849-1936) Thorndike (1874-1959)
History
Early experimental psychology:
Behaviorism Influential figures: !John B. Watson, !B. F. Skinner!
•#Guiding Principles:!–# Only focus on that which is observable.!
–# Explain behavior; not thought, the mind, consciousness, etc.!
•#Contribution to Cognitive Psychology!–#Emphasis on rigorous experimentation.!–#Powerful theories of learning!
•# Classical Conditioning (Ivan Pavlov)!
–# e.g., Pavlov!s dog learned relationship between bell and food.!
•# Operant Conditioning (Edward Thorndike)!
–# e.g., A dog learns to sit for a treat.!
Burrhus Skinner!
1904-1990
John Broadus Watson
1878-1958
“Give me a dozen healthy infants, well-formed, and my own specified world to bring them up in and I'll guarantee to take any one at random and train him to become any type of specialist I might select – doctor, lawyer, artist, merchant-chief and, yes, even beggar-man and thief, regardless of his talents, penchants, tendencies, abilities, vocations, and race of his ancestors. I am going beyond my facts and I admit it, but so have the advocates of the contrary and they have been doing it for many thousands of years. [Behaviorism (1930), p. 82]!
John Broadus Watson
1878-1958
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The Decline of Behaviorism
•# A controversy over language acquisition!
•# Skinner (1957)!
–#Argued children learn language through operant conditioning!
•# Children imitate speech they hear!
•# Correct speech is rewarded
•# Noam Chomsky (1959)!
–#Argued children do not only learn language through imitation and reinforcement!
•# Children say things they have never heard and can not be imitating !
•# Children say things that are incorrect and have not been rewarded for!
–#Language must be determined by inborn biological program (LAD)!
–# “Colorless green ideas sleep furiously”
The Decline of Behaviorism
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•# What happens when the rats are placed in a different arm of the
maze?!
•# The rats navigated to the specific
arm where they previously found food!
–#Supported Latent Learning, not
stimulus-response learning!
Edward Chace Tolman
1886-1959
(a)#Rat initially explores the maze; !
(b)#then learns to turn right to obtain food at B when it starts at A; !(c)#when placed at C, the rat turns left to reach the food at B.
•#Tolman (1938)!
Limitations of Behaviorism
•# Failures to account for aspects of human behavior!
•# Over-emphasis on animal experimentation!
•# Language!•# Skinner suggested language was learned through basic
principles of operant conditioning.!
•# i.e., we learn to say what is rewarded!
•# Fails to account for Generativity of language.!
•# The creation of novel utterances %
that have never been rewarded in the past.!
•# e.g., Chomsky (linguist)
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!#Failure to consider intervening mental processes!
"#Behaviorism:!
"#Cognitive Psychology:!
Stimu
li Response
s
Stimu
li Mental
Processes Response
s
"#Stimulus (memorize this list)!
!# lion, onion, Bill, firefighter, carrot, %
zebra, John, clerk, Tom, nurse, cow!
"#Response (recall)!
!# lion, zebra, cow, onion, carrot, %
firefighter, clerk , nurse, John, Bill, Tom!
"#Mental Processes!
!# Strategies, grouping, reorganization, etc
The Cognitive Revolution
•# Shift from behaviorist"s stimulus-response relationships to an approach that attempts to
explain behavior in terms of the mind
FIG 1.12
Timeline showing events associated with the
decline of the influence of behaviorism (above the
line) and events that led to the development of
the information-processing approach to cognitive
psychology (below the line).
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!#Philosophy!!#Think about mental processes!
!#Structuralism (Introspection)!!#Try to directly tap into mental processes!
!#The What of experience!
!#Behaviorism!
!#Study stimulus-response relationships!
!#Ignore mental processes!
!#Cognitive Psychology!!#Study stimulus-response relationships!
!#Make inferences about mental processes!
!#The How of experience!
!#Mathematical Modeling!
Overview of Different Approaches
Stimu
li Mental
Processes Response
s
The rebirth of the study of the mind
•# The digital revolution!–# Information Processing: inputs are
transformed, in stages, to generate outputs.!
–#Flow diagrams for digital computers.!
•# Flow diagrams for the mind.!–#Colin Cherry (1953): selective attention.!
–#Broadbent"s information processing model of
attention.
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A model for selective attention!
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How can you stay focused on your
conversation?!
You must filter out extraneous
information.
Filter Detector Inputs To memory
“I hate that Shaw guy.”!
Attention can still be broken into.!
(we will explore these ideas more in
chapter 4).
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Studying the Mind
•# To understand complex cognitive behaviors:
•# Measure observable behavior
•# Make inferences about underlying cognitive
activity
•# Consider what this behavior says about how
the mind works
Researching the Mind
•# Behavior approach measures relationship
between stimuli and behavior
•# Physiological approach measures
relationship between physiology and behavior
•# Both contribute to our understanding of
cognition
Researching the Mind – Memory Consolidation
•# Memory for recent events is fragile
•# If processing is disrupted, recent memories
can fail to be consolidated
•# New information can interfere with memory
consolidation
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Researching the Mind – Memory
Consolidation
•# Behavior approach
•# Muller and Pilzecker (1900) had participants
learn two lists of words
•# Independent variable:
•# One group learned the second list immediately after the first list
•# The other group experienced a six-minute delay
between learning the lists
•# Dependent variable:
•# Memory (recall) for the first list of words
Results of the Gais et al. (2007) experiment in which memory for
word pairs was tested for two groups. The sleep group went to
sleep shortly after learning a list of word pairs. The awake group
stayed awake for quite a while after learning the word pairs. Both
groups did get to sleep before testing, so they were equally rested
before being tested, but the performance of the sleep group was
better.
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Cognitive Science •# Interdisciplinary study of the mind
•# Psychology
•# Computer science
•# Cognitive anthropology
•# Linguistics
•# Neuroscience
•# Philosophy
•# Physiology
•# Molecular Biology
•# Physics
•# Education
Timeline showing early experiments studying the mind in the 1800s
and events associated with the rise of behaviorism in the 1900s
Descartes
1596-1640
Broca
1824-1880 Wernicke 1848–1905 Luria (1902-1977)
Pavlov (1849-1936) Thorndike (1874-1959)
Cognitive Neuroscience!
•# The microstructure of the brain
•# Neurons
•# Glia
•# Hold neurons in place,
•# Supply nutrients and oxygen to neurons
•# Insulate neurons from one another
•# Destroy pathogens and remove dead neurons.
•# Also involved in communication
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History of Neuroanatomy
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a) Action potentials are recorded from neurons with tiny microelectrodes that are positioned inside or right next to the neuron’s axon. These potentials are displayed on the screen of an oscilloscope and are also sent to a computer for analysis. (b) An action potential recorded by a microelectrode looks like this. The inside of the axon becomes more positive, then goes back to the original level, all within 1 millisecond (1/1,000 second). (c) A number of action potentials displayed on an expanded time scale, so a single action potential appears as a “spike”.
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Microstructure: The Neuron
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The Action Potential •# Remember that voltage is a difference between two locations!
•# the voltage between two points is equal to the electrical potential difference between those points.
•# Electric potential is the energy required to move a unit electric charge to a particular place in a static electric field
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Microstructure: The Synapse
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